Research has shown that chemicals in tea are released at different temperatures and at different rates. For example, the aromatic compounds in tea leaves are released into the tea beverage (the infusion of water and tea leaves) within the first 5 to 30 seconds of the tea leaves being bathed in hot water, with temperature of the hot water in the range of 65˜100° C. Other compounds that greatly contribute to the taste of the tea beverage are released at a slower rate, thus requiring a longer hot water bath for the release to take place. To make matters more complicated, some important compounds actually start to break down and lose their flavors and potency at different temperatures and times. Mismatched time/temperature equations sometimes cause chemical reactions that form undesirable characteristics in the tea, e.g., bitterness.
Taking Oolong tea as an example, Oolong teas are famous for their aromatic and complex flavors. High quality ball-shaped Oolong teas are historically prepared using only the top two leaves and the bud of the Camellia sinensis tea plant. To prepare Oolong tea, one common practice calls for adding 10 grams of tea to 235 ml of hot water at 90° C. for three minutes. However, such method of brewing Oolong tea may risk not bringing out the best of Oolong tea as well as causing undesirable results such as bitterness, for example.
Moreover, in many home or retail settings (e.g., teashop, coffee shop or restaurants), a dose of loose-leaf tea is infused only a single time and often for long periods of time. However, this is not the best combination for optimal brewing.